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authorCatalin Marinas <catalin.marinas@arm.com>2012-03-05 11:49:29 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 13:42:04 +0100
commitfc47897d2c65bc94b6868a5c914afbd33216e26f (patch)
tree0926daf682eba58fe67995d7b3c7c1bc65ea58e9 /arch/arm64/mm
parent6170a97460dbda12686bef0dec65ce2d59867f9e (diff)
downloadlinux-fc47897d2c65bc94b6868a5c914afbd33216e26f.tar.gz
arm64: Device specific operations
This patch adds several definitions for device communication, including I/O accessors and ioremap(). The __raw_* accessors are implemented as inline asm to avoid compiler generation of post-indexed accesses (less efficient to emulate in a virtualised environment). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Diffstat (limited to 'arch/arm64/mm')
-rw-r--r--arch/arm64/mm/ioremap.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
new file mode 100644
index 00000000000..1725cd6db37
--- /dev/null
+++ b/arch/arm64/mm/ioremap.c
@@ -0,0 +1,84 @@
+/*
+ * Based on arch/arm/mm/ioremap.c
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * Hacked for ARM by Phil Blundell <philb@gnu.org>
+ * Hacked to allow all architectures to build, and various cleanups
+ * by Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/io.h>
+
+static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
+ pgprot_t prot, void *caller)
+{
+ unsigned long last_addr;
+ unsigned long offset = phys_addr & ~PAGE_MASK;
+ int err;
+ unsigned long addr;
+ struct vm_struct *area;
+
+ /*
+ * Page align the mapping address and size, taking account of any
+ * offset.
+ */
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(size + offset);
+
+ /*
+ * Don't allow wraparound, zero size or outside PHYS_MASK.
+ */
+ last_addr = phys_addr + size - 1;
+ if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
+ return NULL;
+
+ /*
+ * Don't allow RAM to be mapped.
+ */
+ if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
+ return NULL;
+
+ area = get_vm_area_caller(size, VM_IOREMAP, caller);
+ if (!area)
+ return NULL;
+ addr = (unsigned long)area->addr;
+
+ err = ioremap_page_range(addr, addr + size, phys_addr, prot);
+ if (err) {
+ vunmap((void *)addr);
+ return NULL;
+ }
+
+ return (void __iomem *)(offset + addr);
+}
+
+void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
+{
+ return __ioremap_caller(phys_addr, size, prot,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(__ioremap);
+
+void __iounmap(volatile void __iomem *io_addr)
+{
+ void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
+
+ vunmap(addr);
+}
+EXPORT_SYMBOL(__iounmap);